Structure 17624A0000000 · King County, WA

Benson Road over I-405

Carries Benson Road over I-405, 0.1 N Jct SR 515.

Overall conditionGood

Set by its lowest-rated component: Deck and Superstructure and Substructure at 8 of 9.

How ratings work
Decksets the rating8/9 · Very Good
Superstructuresets the rating8/9 · Very Good
Substructuresets the rating8/9 · Very Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT520 FT OVERALL100 FT0ELEVATION · LENGTHS TO SCALE
Deck 8/9Superstructure 8/9Substructure 8/9

520 ft end to end, longest span 207 ft: about 7 semi-trucks nose to tail. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a multi-beam bridge.

Built201016 years old
Length520.0 ft158.5 m
Daily traffic9,777counted 2010
Last inspectedApril 2024every 24 months

Location

StateWashington
CountyKing
Location0.1 N Jct SR 515
CarriesBenson Road
CrossesI-405
Coordinates47.47031, -122.20639

Physical Characteristics

MaterialPrestressed Concrete Continuous
DesignStringer/Multi-beam
Total Length520.0 ft (158.5 m)
Max Span207.0 ft (63.1 m)
Deck Width43.0 ft (13.1 m)
Deck Area2076.3 sq m
Main Spans3
Year Built2010

Traffic

Avg Daily Traffic9,777 (2010)
Truck Traffic8%
Lanes On Bridge2
Lanes Under Bridge11

Inspection & Ownership

Last InspectionApril 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceHistorical significance is not determined
Scour CriticalNot applicable
Structure Number0017624A0000000

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

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